(a) Why was the term inert gases dropped? (b) What discovery triggered this change in name? (c) What name is applied to the group 18 elements now?

Verified step by step guidance

1. Step 1: Understand the term 'inert gases'. Historically, the noble gases were called 'inert gases' because they were thought to be completely nonreactive due to their full valence electron shells.
2. Step 2: Explore the discovery that led to the change. In 1962, chemist Neil Bartlett discovered that xenon, a noble gas, could form compounds, specifically xenon hexafluoroplatinate (XePtF6), demonstrating that these gases are not completely inert.
3. Step 3: Recognize the implications of this discovery. The ability of noble gases to form compounds under certain conditions showed that they are not entirely nonreactive, which led to the reconsideration of the term 'inert'.
4. Step 4: Identify the new terminology. As a result of these findings, the term 'noble gases' became more widely used, reflecting their general lack of reactivity while acknowledging their ability to form compounds.
5. Step 5: Confirm the current name for group 18 elements. Today, the elements in group 18 of the periodic table are commonly referred to as 'noble gases'.

Key Concepts

Inert Gases vs. Noble Gases

The term 'inert gases' was historically used to describe the elements in Group 18 of the periodic table, which were thought to be completely nonreactive due to their full valence electron shells. However, this term was dropped as it became clear that these gases could participate in chemical reactions under certain conditions, leading to the adoption of the more accurate term 'noble gases.'

Discovery of Chemical Reactivity

The change in terminology from 'inert gases' to 'noble gases' was largely influenced by the discovery that some of these gases, particularly xenon and krypton, could form compounds with highly electronegative elements like fluorine. This revelation demonstrated that even the most stable elements could engage in chemical reactions, challenging the notion of complete inertness.

Group 18 Elements

Group 18 of the periodic table, now referred to as the noble gases, includes helium, neon, argon, krypton, xenon, and radon. These elements are characterized by their full outer electron shells, which contribute to their low reactivity and unique properties, such as being colorless, odorless, and monatomic under standard conditions.